Two sources familiar with Blumenthal's appearance before the grand jury said he refused to discuss his conversations with Clinton about former White House intern Monica Lewinsky. White House lawyers and Starr are sparring over whether such conversations are protected by executive privilege.

The grand jury is looking into reports that Clinton had a sexual relationship with Lewinsky and encouraged her to lie about it under oath. Clinton has denied both accusations.

A lawyer familiar with the investigation tells CNN that Vernon Jordan, the Washington lobbyist and Clinton confidant, has been informed he is likely to be called before the grand jury next week.

Starr is investigating whether Jordan's efforts to get Lewinsky a private-sector public relations job in New York was part of an effort to buy her silence in the Paula Jones sexual harassment case. Jordan has denied that, and said Lewinsky told him she did not have a sexual relationship with the president.

Starr also is interested in Jordan's referral of Lewinsky to Washington attorney Frank Carter, who took a sworn statement from her denying an sexual relationship with the president.

On another front, a legal source confirms that Starr has subpoenaed two former Arkansas state troopers who now do private investigative work. The two are being called before a federal grand jury in Little Rock, Ark., next week.

They are Bill Mullenax and Tommy Goodwin. Mullenax runs an investigative firm called Mid-South Safety Council and Goodwin once worked there. The source said Starr wants to know if they were hired to do any work looking into the private lives of Starr and his staff and if they had any contacts with Blumenthal or Clinton lawyer Mickey Kantor.

USA Today quoted the men as saying their work had nothing to do with Starr and that they had no contact with Blumenthal or Kantor.

Blumenthal attorney William McDaniel issued a statement, saying, "Sidney Blumenthal does not know these investigators. Mr. Blumenthal has never spoken to them or to any other private investigators in Arkansas or anywhere else about Starr or Starr's staff. Mr. Blumenthal has had no communications whatsoever with The National Enquirer, reportedly the employer of the Arkansas investigators."

The family of Lewinsky has chosen a Los Angeles accounting firm to establish and administer a legal defense fund for her, CNN has learned.

Sources said the Lewinsky family moved quickly to establish an authorized legal defense fund after a New York woman announced she planned to create one. Lewinsky attorney Bill Ginsburg quickly distanced his client from that effort.

The official fund is incorporated as the "Monica Lewinsky Defense Trust Fund" and the documents say the money raised will be used to cover attorneys fees and other expenses related to defending her from Starr's grand jury investigation.